Bsrgvty

I recently set up a machine with Ubuntu Server to host game servers. I installed a backup plugin for each game server that creates frequent backups of game world files in a particular folder on the machine. I also established a cron task to automatically copy those backups to my Dropbox folder every night using rsync with the -a option.

After a few months my Dropbox account reached its storage limit and I realized I would not be able to keep so many backups, so I configured the game server backup plugin to not retain so many backups, then waited a few days to see if it would delete the older backups as it is scheduled to do on a weekly basis. The backup plugin eventually did its job and deleted the older backups, so I was expecting the rsync cron task to subsequently delete the older backups from my Dropbox folder to match the source folder, but it has not done so. So I have a couple of questions:

• By default, does rsync only add files to the destination folder
  that have been added to the source folder and change files that
  have been changed in the source folder but NOT delete files
  that were deleted from the source folder?




• If that is the case, what is the best way to make rsync do this? I
  want the destination folder to perfectly reflect the source folder,
  and that means deleting any files that have been deleted from the source
  folder.

I see some options listed in the manual page for rsync that might do the trick, but since I'm not familiar with.

To delete files in the target, add the --delete option to your command. For example:

rsync -avh source/ dest/ --delete

The rsync command wont delete any file while you use some of its options delete in that command. So if any file or folder added in source, it'll be synced to target without any deletion.

I suggest you to use rsync for make backup from source files and use find ... rm for deletion files for period of time or size of files:

rsync [options] SOURCE TARGET
find TARGET -maxdepth 1 -type f -mtime +60 -exec rm -f ;

The above code block, make a backup from source and then delete every files which last modified time are more than 2 month.

UPDATE

As I find that the delete options are just for TARGET that if some files are removed from source, rsync --delete remove them from TARGET. And the delete option by after and before, as mentioned in its man page:

--delete-before receiver deletes before transfer, not during

Means that:

1. rsync delete the file from TARGET which are removed from SOURCE.


2. rsync start syncing files.

--delete-after receiver deletes after transfer, not during

Means that:

1. rsync start syncing files.


2. rsync delete the file from TARGET which are removed from SOURCE after syncing.

NOTE: the --delete-before/after implement just in TARGET.

This command will copy increment data and keep it in sync with remote server.

1. It will copy only incremental data.


2. It will delete if any data deleted from source.


3. It will copy again from source if any data deleted at destination.


4. basically this command will keep the both environment in sync.

rsync -avWe ssh --delete-before (source) root@localhost:(destination)
rsync -avW --delete-before -e ssh (source) root@localhost:(destination)

Example:

rsync -avWe ssh --delete-before /data root@192.168.254.254:/backup
rsync -avW --delete-before -e ssh /data root@192.168.254.254:/backup

If there are any errors during an rsync scync, rsync will not properly delete the files it should have, even if you used --delete, --delete-after, or --delete-before.

This is why it is important to address rsync errors.

Most of my errors were due to using the --perms option while syncing with a Non-Linux file system. When I replaced --perms with --no-perms, those errors went away and then deleting worked.

--perms is ok when you are syncing from a Linux file system to a another Linux file system, but if you're syncing from Linux to a Non-Linux file system (like NTFS, FAT), --perms causes errors because rsync cannot set Linux permissions on a non-linux file systems. Again, errors = no delete.

-- When syncing to a Non-Linux partition, I use --no-perms to avoid those errors that sabotage --delete, --delete-after, or --delete-before.

If you still get errors after that, and cannot figure out how to make those errors go way, you can run a command that is exclusively dedicated to deleting the out-of-sync files:

sudo rsync -r --delete --existing --ignore-existing --ignore-errors --progress /path/to/source/ /path/to/destination

The command above will delete stuff that's out of sync, but won't sync any files. So, you should sync again after this. That command is based off of this answer, except that I added the --ignore-errors argument also, so it would delete even if there are errors.